Resolves an issue with the generator script to build the dfa for Python syntax.

Fixes a critical issue in the register allocator and extends support on s390x.
PyPy runs and translates on the s390x revisions z10 (released February 2008, experimental)
and z196 (released August 2010) in addition to zEC12 and z13.
To target e.g. z196 on a zEC12 machine supply CFLAGS=”-march=z196” to your shell environment.

Implement the backend related changes for s390x.

Simplify handling of interp-level tests and make it more forward-
compatible.

Sync w_file with the c-level FILE* before returning FILE* in PyFile_AsFile

Allow rw access to the char* returned from PyString_AS_STRING, also refactor
PyStringObject to look like cpython’s and allow subclassing PyString_Type and
PyUnicode_Type

Bug fix: if socket.socket() failed, the socket.error did not show
the errno of the failing system call, but instead some random previous
errno.

Refactor PyTupleObject to look like cpython’s and allow subclassing
PyTuple_Type

Use offsets from PyTypeObject to find actual c function to call rather than
fixed functions, allows function override after PyType_Ready is called

Avoid exhausting the stack in the JIT due to successive guard
failures in the same Python function ending up as successive levels of
RPython functions, while at app-level the traceback is very short

Try harder to memory to the OS. See e.g. issue #2336. Note that it does
not show up as a reduction of the VIRT column in top, and the RES
column might also not show the reduction, particularly on Linux >= 4.5 or
on OS/X: it uses MADV_FREE, which only marks the pages as returnable to
the OS if the memory is low.

Fill in more slots when creating a PyTypeObject from a W_TypeObject
More slots are still TBD, like tp_print and richcmp

Rewrite the Win32 dependencies of ‘subprocess’ to use cffi instead
of ctypes. This avoids importing ctypes in many small programs and
scripts, which in turn avoids enabling threads (because ctypes
creates callbacks at import time, and callbacks need threads).

The new logging facility that integrates with and adds features to vmprof.com.

Resolve issues to use the new logging facility on a 32bit system

Trying harder to make hash(-1) return -2, like it does on CPython

Log exact line positions in debug merge points.

Allocate all RPython strings with one extra byte, normally unused.
It is used to hold a final zero in case we need some char*
representation of the string, together with checks like notcan_move() or object pinning. Main new thing that this allows:
ffi.from_buffer(string) in CFFI. Additionally, and most
importantly, CFFI calls that take directly a string as argument don’t
copy the string any more—this is like CFFI on CPython.

Add a new command line option -X track-resources which will produce
ResourceWarnings when the GC closes unclosed files and sockets.

Implement PyObject_Realloc

Improve a little bit the readability of the generated C code

Improved vmprof support: now tries hard to not miss any Python-level
frame in the captured stacks, even if there is the metainterp or
blackhole interp involved. Also fix the stacklet (greenlet) support.

type.__dict__ now returns a dict_proxy object, like on CPython.
Previously it returned what looked like a regular dict object (but it
was already read-only).

Reduce the size of the generated C code by constant-folding we_are_jitted
in non-jitcode.